Multiple choice

In a class of 40 students, the average weight of the boys is 70 kg, and the average weight of the girls is 55 kg. If the number of boys is 25 and the average weight of the tallest 10 students in the class is 75 kg, what is the average weight of the remaining students?

  1. 38.57 kg

  2. 43.77 kg

  3. 56.83 kg

  4. 60.83 kg

  5. a
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Total weight = (25 * 70) + (15 * 55) = 1750 + 825 = 2575. Weight of top 10 = 10 * 75 = 750. Remaining weight = 2575 - 750 = 1825. Remaining students = 30. Average = 1825 / 30 = 60.833.

AI explanation

Using the weighted average formula, the total weight of the class is calculated by adding the total weight of the boys to the total weight of the girls. The total weight of the 25 boys is 25 multiplied by 70 kg, which equals 1750 kg. The total weight of the 15 girls is 15 multiplied by 55 kg, which equals 825 kg, giving a combined class weight of 2575 kg. The total weight of the tallest 10 students is 10 multiplied by 75 kg, equaling 750 kg. Subtracting this from the class total leaves 1825 kg for the remaining 30 students. Dividing 1825 kg by 30 students gives an average weight of 60.83 kg.

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